#include<iostream>
#include<string>
#include<regex>

using namespace std;

int main()
{
    string str="/abc/44455/";
    regex e("/abc/(\\d+)");
    smatch matches;
    bool ret=regex_match(str,matches,e);
    if(ret==false) return -1;
    for(auto &s:matches)
    {
        cout<<s<<endl;
    }    
    return 0;
}